Re: [PATCH V2 1/2] mmc: sdhci-msm: Add interconnect bandwidth scaling support

[ppvk]

On 2020-06-05 00:04, Sibi Sankar wrote:
> On 2020-06-04 22:39, Matthias Kaehlcke wrote:
> > On Thu, Jun 04, 2020 at 04:44:42PM +0530, Pradeep P V K wrote:
> > > Interconnect bandwidth scaling support is now added as a
> > > part of OPP [1]. So, make sure interconnect driver is ready
> > > before handling interconnect scaling.
> > >
> > > This change is based on
> > > [1] [Patch v8] Introduce OPP bandwidth bindings
> > > (https://lkml.org/lkml/2020/5/12/493)
> > >
> > > [2] [Patch v3] mmc: sdhci-msm: Fix error handling
> > > for dev_pm_opp_of_add_table()
> > > (https://lkml.org/lkml/2020/5/5/491)
> > >
> > > Signed-off-by: Pradeep P V K <ppvk@xxxxxxxxxxxxxx>
> > > ---
> > >  drivers/mmc/host/sdhci-msm.c | 13 +++++++++++++
> > >  1 file changed, 13 insertions(+)
> > >
> > > diff --git a/drivers/mmc/host/sdhci-msm.c 
> > > b/drivers/mmc/host/sdhci-msm.c
> > > index b277dd7..a13ff1b 100644
> > > --- a/drivers/mmc/host/sdhci-msm.c
> > > +++ b/drivers/mmc/host/sdhci-msm.c
> > > @@ -14,6 +14,7 @@
> > >  #include <linux/slab.h>
> > >  #include <linux/iopoll.h>
> > >  #include <linux/regulator/consumer.h>
> > > +#include <linux/interconnect.h>
> > >
> > >  #include "sdhci-pltfm.h"
> > >  #include "cqhci.h"
> > > @@ -2070,6 +2071,18 @@ static int sdhci_msm_probe(struct 
> > > platform_device *pdev)
> > >  	}
> > >  	msm_host->bulk_clks[0].clk = clk;
> > >
> > > +	/* Make sure that ICC driver is ready for interconnect bandwdith
> > > +	 * scaling before registering the device for OPP.
> > > +	 */
> > > +	ret = dev_pm_opp_of_find_icc_paths(&pdev->dev, NULL);
> > > +	if (ret) {
> > > +		if (ret == -EPROBE_DEFER)
> > > +			dev_info(&pdev->dev, "defer icc path: %d\n", ret);
> >
> > I already commented on this on v1:
> >
> >   This log seems to add little more than noise, or are there 
> > particular reasons
> >   why it is useful in this driver? Most drivers just return silently 
> > in case of
> >   deferred probing.
> >
> > If you think the log is really needed please explain why.
Sorry. i forget to remove this print on V2. i will address this in my 
next patch set.

> Both the err logs seem redundant.
> EPROBE_DEFERS are rather readily
> noticeable through the return val.
> dev_.._find_icc_paths already prints
> err messages when we fail to get icc
> paths.

True. i will remove this too in my next patch set.